Traditionally, a librarian is associated with collections of books, as demonstrated by the etymology of the word "librarian" (from the Latin liber, "book"). The role of a librarian is continually evolving to meet social and technological needs. A modern librarian may deal with provision and maintenance of information in many formats, including: books; electronic resources; magazines; newspapers; audio and video recordings; maps; manuscripts; photographs and other graphic material; bibliographic databases; and web-based and digital resources. A librarian may also provide other information services, including: information literacy instruction; computer provision and training; coordination with community groups to host public programs; assistive technology for people with disabilities; and assistance locating community resources. Appreciation for librarians is often included by authors and scholars in the acknowledgment sections of books.
The Sumerians were the first to train clerks to keep records of accounts. "Masters of the books" or "Keepers of the Tablets" were scribes or priests who were trained to handle the vast amount and complexity of these records. The extent of their specific duties is unknown.
Sometime in the 8th century BC, Ashurbanipal, King of Assyria, created a library at his palace in Nineveh in Mesopotamia. Ashurbanipal was the first individual in history to introduce librarianship as a profession. We know of at least one "keeper of the books" who was employed to oversee the thousands of tablets on Sumerian and Babylonian materials, including literary texts; history; omens; astronomical calculations; mathematical tables; grammatical and linguistic tables; dictionaries; and commercial records and laws. All of these tablets were cataloged and arranged in logical order by subject or type, each having an identification tag.
The Great Library of Alexandria, created by Ptolemy I after the death of Alexander the Great in 323 BC, was created to house the entirety of Greek literature. It was notable for its famous librarians: Demetrius, Zenodotus, Eratosthenes, Apollonius, Aristophanes, Aristarchus, and Callimachus. These scholars contributed significantly to the collection and cataloging of the wide variety of scrolls in the library's collection. Most notably, Callimachus created what is considered to be the first subject catalogue of the library holdings, called the pinakes. The pinakes contained 120 scrolls arranged into ten subject classes; each class was then subdivided, listing authors alphabetically by titles. The librarians at Alexandria were considered the "custodians of learning".
Near the end of the Roman Republic and the beginning of the Roman Empire, it was common for Roman aristocrats to hold private libraries in their home. Many of these aristocrats, such as Cicero, kept the contents of their private libraries to themselves, only boasting of the enormity of his collection. Others, such as Lucullus, took on the role of lending librarian by sharing scrolls in their collection. Many Roman emperors included public libraries into their political propaganda to win favor from citizens. While scholars were employed in librarian roles in the various emperors' libraries, there was no specific office or role that qualified an individual to be a librarian. For example, Pompeius Macer, the first librarian of Augustus' library, was a praetor, an office that combined both military and judicial duties. A later librarian of the same library was Gaius Julius Hyginus, a grammarian.